“This the first time since the Pew Internet Project began measuring e-reader use in April 2009 that ownership of this device has reached double digits among U.S. adults,” Pew says in the report.

In contrast, ownership of tablet computers has grown more slowly, to 8% of U.S. adults in May from 5% in November, the report says. The report notes that 9% of U.S. adults own an e-reader but not a tablet, 5% own a tablet but not an e-reader, and 3% own both devices.

Ownership of e-readers is most common among people living in households with annual incomes of $75,000 or more (24% own an e-reader), college graduates (22%), Hispanic adults (15%), and adults between the ages of 30 and 49 (14%), the report says. E-readers are also more common among parents of children under 18 (16%) than other adults (10%).

For tablets, ownership is more common among men (10%) than women (6%). Other groups with relatively high levels of tablet ownership include consumers living in households with incomes of $75,000 or more (17%), Hispanic adults (15%), college graduates (13%), and consumers between the ages of 18-29 (12%).

Still, ownership levels for e-readers and tablets trail that of other devices important to e-commerce. According to Pew, these are ownership rates among U.S. adults for the following devices, as of May:

● Cell phone, 83%

● Desktop computer, 57%

● Laptop, 56%

● DVR, 52%

● MP3 player, 44%

● E-reader, 12%

● Tablet, 8%

Pew based its finding on a survey of 2,277 U.S. adults 18 and older conducted between April 26 and May 22, 2011.